Epoxy resin composition

Abstract

A novel epoxy resin composition is comprised of a mixture of a cyclic epoxide type epoxy resin having an epoxy equivalent of 200 or below and a phenoxy resin having a molecular weight of approximately 30,000, a curing agent, and an inorganic filler. This resin composition is useful in the fabrication of cast insulators to be employed in electric machines.

I claim: 
     
       1. An epoxy resin composition comprising an epoxy resin which is a mixture (A) of an epoxy resin having an epoxy equivalent of 200 or below and a phenoxy resin having a molecular weight of approximately 30,000, a curing agent which is made of a polybasic carboxylic acid anhydride and an aromatic ester, and an inorganic filler powder, wherein the epoxy resin in the mixture (A) is 3,4-epoxycyclohexylmethyl-(3,4-epoxy)cyclohexanecarboxylate and wherein the aromatic ester is a diester of Formula (I): ##STR2## wherein R 1  and R 2  are each a saturated or unsaturated cyclic hydrocarbon group having 6-8 carbon atoms. 
     
     
       2. An epoxy resin composition according to claim 1 wherein the phenoxy resin in said mixture (A) is present in an amount of 10-50 wt% of the expoxy resin. 
     
     
       3. An epoxy resin composition according to claim 1 wherein the aromatic ester as one component of the curing agent is present in an amount of 0.05-0.3 mole per mole of the polybasic carboxylic acid anhydride.